The invention relates to a side-folded bag or sack of a flexible material, which is to be filled with a pourable material.
Known side-folded bags or sacks of this type consist of paper, plastic sheets or multilayer or composite materials, which may comprise plastic films or sheets, metal foil and paper layers and, after being filled with the pourable, for example grainy, material in an optionally separate filling process, are closed off on the inside at their head end in seam fashion with one another or with the in each case adjoining half of the side fold. The formation of this connecting or closing seam at the head end takes place preferably with the help of a hot-melt or hot-scaling adhesive, which is applied with the help of the bag producer along the upper edge of the head end on the inside of the bag and activated by heat to form a sealed closing seam. However, if the inside of the bag itself has to a sufficient degree the properties of a hot-melt adhesive for forming the sealed closing seam, the application of such a hot-melt adhesive can be omitted and the sealed closing seam can be produced directly at the upper edge of the bag with the help of conventional sealing jaws.
The handle at the upper edge of the bag, which is assigned to the inner folded edge of one of the two side folds, makes it easier in the case of such bags or sacks to pull out the side fold, the connecting seam between front and rear walls of the bag and the side fold half, which in each case adjoins, being undone in order to form a discharging opening for pouring material from the bag. If, as is the case particularly with larger bags or sacks, the contents of the bag are not to be removed in a single process and, instead, only partial amounts are to be removed in several pouring processes, which are more or less spaced apart in time, it is desirable, for the protection of the material remaining in the bag, to close once again the discharging opening, formed by opening the side fold. For this purpose, it is generally not sufficient to push the side fold back into the position, which it had assumed originally in the closed head end of the bag, since the elasticity of the usual bag material permits the side fold to spring open once again more or less and thus create an opening to the interior of the bag, which prevents effective protection of the contents of the bag.